After 15 seasons the popular CW show Supernatural will wrap up this fall. On more than one occasion the Winchester brothers have used the word 'Poughkeepsie' as an important code word.

Starring Jared Padelecki as Sam Winchester and Jensen Ackles as Dean Winchester the popular television series chronicles their struggles with, you guessed it, the supernatural. Over the course of the series, they've battled demons, monsters, and other beings from beyond.

According to the Supernatural fansite Fandom, the word Poughkeepsie is used as the brothers' distress signal when things are going wrong. No explanation is given as the reason why but it's used twice in season nine and again in season 14 a few years later.

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In the first instance, while working with the powerful demon Crowley, Crowley enters Sam's head in an effort to release him from possession by the outlaw angel Gadreel. Crowley utters the word 'Poughkeepsie' but Sam doesn't believe Crowley is helping at first.

You can view the full scene below. Months later Crowley uses the code word again to alert Sam & Dean that they're being led into a trap. Fast forward to season 14, 'Poughkeepsie' is used again when Sam is trying to help expel an archangel from Dean's body.

The final season of Supernatural will resume airing in October with the final episode scheduled for November 19.

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